Coverage region
Engineering Services Across San Antonio and South Central Texas
Thirteen counties along the Balcones Escarpment. The single most useful fact about engineering here is that the escarpment runs through Bexar County, and the soil on either side of it is not the same soil.
Wind
What the wind here asks of a structure
What the wind environment requires of a structure in San Antonio and South Central Texas.
This region is fully inland. There is no windstorm certification requirement, and design wind speeds are moderate by Texas standards, which puts the governing load on gravity and on soil rather than on wind for most residential structures.
Hail and severe thunderstorm wind still reach the region regularly, and the Hill Country counties see damaging downslope wind events that surprise structures designed only to the mapped speed.
Flash flooding is the more distinctive hazard here. The escarpment turns Hill Country rainfall into fast moving water, and site and foundation decisions on stream adjacent property are made with scour and hydrostatic loading in view.
Soil
What the ground does, and what it does to a foundation
What the ground does here, and what a foundation has to be designed against because of it.
The Balcones Escarpment divides the region and it divides the engineering with it. North and west of it, in Kendall, Kerr, Bandera, Gillespie, and northern Bexar county, soils are thin over Edwards limestone, rock is often within a few feet of the surface, and the foundation problem is excavation and bearing on irregular rock rather than expansion.
South and east of the escarpment the region sits on Taylor and Del Rio clays and the marls beneath them, with high plasticity and pronounced seasonal movement. Southern and eastern Bexar, Wilson, Guadalupe, Atascosa, Medina, and Frio counties behave much more like the Blackland Prairie than like the Hill Country twenty miles away.
Karst features complicate the limestone side. Voids, solution cavities, and infilled sinkholes are encountered in the Edwards outcrop, and a foundation investigation that assumes uniform rock bearing on that terrain is assuming too much.
Permitting
Who has authority, and what they ask for
Who has authority over the work, and what they ask for before they issue.
The City of San Antonio permits within its limits and exercises authority in its extraterritorial jurisdiction, and Bexar County permits in unincorporated areas. New Braunfels, Schertz, Boerne, Seguin, and Kerrville each operate their own departments with their own adopted editions.
The Edwards Aquifer Recharge Zone adds a regulatory layer that exists almost nowhere else in the state. Development over the recharge and contributing zones requires a water pollution abatement plan approved by the Texas Commission on Environmental Quality, and that review runs on its own schedule alongside the building permit.
The Interstate 35 corridor from San Antonio through New Braunfels is among the fastest growing areas in the country, and the jurisdictions along it have been revising their requirements to keep pace. Confirming the adopted code edition at the start of a project is worth more here than in a settled market.
Service emphasis
What this region asks for most
All 8 service lines are available across the state. These are the ones the conditions above push to the front here.
Foundation Inspections and Certifications
Two very different soil regimes meet inside one metropolitan county.
Residential and Light Commercial Design
Sustained construction growth along the Interstate 35 corridor.
Structural Letters for Permits
Active municipal permitting across the region's incorporated cities.
Solar Structural Letters
High residential solar adoption across the metropolitan area.
Counties
The 13 counties in this region
Population centers include San Antonio, New Braunfels, Kerrville, Boerne, Seguin, Fredericksburg. Coverage is the whole list, not the centers.
- Atascosa
- Bandera
- Bexar
- Comal
- Frio
- Gillespie
- Guadalupe
- Karnes
- Kendall
- Kerr
- McMullen
- Medina
- Wilson
Elsewhere in Texas
The other seven regions
Start a job
Tell us what the letter is for and we will tell you yes or no
Send the address, what the document is for, and the date it has to be in hand. Some jobs this firm cannot take, and you will hear that in the first conversation rather than after you have paid and waited.